Ion exchange and electrochemical methods and devices employing one-step quaternized and polymerized anion selective polymers

ABSTRACT

The invention provides ion exchange and electrochemical methods and devices employing anion exchange polymers produced by substantially simultaneous quaternization and polymerization reactions. Anion selective polymers are produced in accordance with the invention by combining, an ethylenic tertiary amine monomer, an alkylating agent having a boiling point temperature of at least about 100° C., and a cross-linking agent in the presence of a polymerizing agent for a time and at a temperature sufficient to form the polymer. The alkylating agent and the cross-linking agent may be the same compound, a cross-linking alkylating agent. The polymers may be produced in the presence of solvents and/or in the presence of diluting monomers which are incorporated into the polymers.

FIELD OF THE INVENTION

The present invention relates to the field of ion exchange andelectrochemical methods and devices, and, in particular, to such methodsand devices employing anion selective polymers produced by substantiallysimultaneous quaternization and polymerization reactions.

BACKGROUND OF THE INVENTION

Ion exchange (“IX”) and electrochemical methods and devices using ionexchange structures were initially developed more than 50 years ago, andhave since that time been improved to the point that such systems arecommonly employed to purify fluids for a variety of applications.Typically, IX and electrochemical membrane methods and devices such aselectrodialysis (“ED”) and reversing type electrodialysis (“EDR”) purifyfluid through ion exchange or electric field-mediated transfer of ionsthrough membranes from diluting or permeate streams passing through“less concentrated” compartments to concentrating or brine streamspassing through “more concentrated” compartments. Generally, aniontransfer and cation transfer membranes are alternated in ED methods anddevices, the membranes being placed between an anode (positiveelectrode) and a cathode (negative electrode) across which a DC electricfield is applied transverse to the fluid flow directions. Anion transfermembranes allow passage only of low molecular weight negatively chargedspecies (anions), and cation transfer membranes allow passage only oflow molecular weight positively charged species (cations). Transfer ofions across membranes is mediated by the attraction of anions to theanode and cations to the cathode. The combination of an anode, acathode, and alternating anion and cation transfer membranestherebetween is commonly referred to as an ED “stack” or pack.

FIG. 1 depicts a schematic view of an exemplary ED unit 10 having acathode 12 and an anode 14 and cation transfer membranes 20 alternatingwith anion transfer membranes 22. Cation transfer membranes 20 and aniontransfer membranes 22 form a plurality of alternating ED dilutingcompartments 24 and ED concentrating or brine compartments 26. A fluid,for example water, enters the ED unit 10 at electrode stream inlets 52and exits ED unit 10 at electrode stream outlets 54 to form electrodestreams 50. The electrode streams 50 that comes into contact withcathode 12 or with anode 14 do not mix with, and are not in fluidcommunication with, fluid in ED feed stream 30 or with fluid in ED brinestream 40 (see below).

Fluid to be purified flows into ED unit 10 in the form of ED feed stream30 which enters the unit at ED feed stream inlet 32. ED feed streaminlet 32 is in fluid communication with ED feed stream inlet manifold34, through which fluid to be purified is delivered to one or more EDdiluting (less concentrated) compartments 24. The number of dilutingcompartments 24 in an ED unit can vary according to the application inwhich the ED unit is used. Determinations of the appropriate number ofdiluting compartments for a particular application can be accomplishedempirically, on the basis of the desired capacity of the fluidpurification system and the amount and identity of contaminants in thefeed stream. As defined herein, diluting compartment 24 of ED unit 10involves the sum of all diluting compartments contained within the unit.After traversing the diluting compartment 24, fluid from ED feed stream30 enters ED product stream outlet manifold 36, exiting the ED unit asless concentrated product stream 30 a at ED product stream outlet 38.Fluid is purified in the ED diluting compartments 24 by virtue ofpassage of ions out of the ED diluting compartments 24 into the moreconcentrated ED concentrating or brine compartments 26.

In parallel to the flow of ED feed stream 30, an ED concentrate or brineinfluent 40 flows into unit 10 at ED concentrate or brine stream inlet42. ED concentrate or brine stream inlet 42 is in fluid communicationwith ED concentrate or brine stream inlet manifold 44, through whichfluid that receives ions from the ED diluting compartments 24 isdelivered to one or more ED concentrating or brine compartments 26. Thenumber of concentrating or brine compartments in an ED unit may varyaccording to the application in which the ED unit is used, but will beequal to (or±1) the number of diluting compartments in the unit. Inaccordance with the invention, concentrating or brine compartment 26 ofED unit 10 comprises the sum of all concentrating or brine compartmentscontained within the unit. After traversing the ED concentratingcompartment 26, fluid from ED concentrate or brine influent 40 enters EDconcentrate or brine stream outlet manifold 46, exiting the ED unit atED concentrate or brine stream outlet 48. After exiting from EDconcentrate or brine stream outlet 48, all or at least a portion of thebrine stream is discarded as “blowdown”, and the remainder, if any, ofthe effluent brine stream is recycled into concentrate or brine influent40, upstream of brine stream inlet 42.

Anion selective polymers for use in anion exchange resins or transfermembranes involved in the electrochemical devices and processesdescribed above may be manufactured via a variety of techniques. Forexample, anion selective polymers may be prepared by co-polymerizingmethacrylate esters containing amine groups of the tertiary type, withcross-linking methacrylate esters (see for example U.S. Pat. No.4,231,855 by Hodgdon et al.). The resulting polymer with pendanttertiary amine groups may be quaternized with an alkyl halide, such asmethyl chloride, so that the tertiary amine groups are converted toquaternary ammonium salts.

The above-described technique may require washing steps between processsteps and requires chemical reactions on polymerized sheets. Further,exchange resins and transfer membranes formed of methacrylate esters maydegrade rapidly in the presence of caustic solutions. In addition,exchange resins and transfer membranes formed by the above-identifiedtechnique may lack resiliency and further, the membranes may leak,because the post-polymerization quaternization reactions may weaken theresin.

Anion selective polymers for use in anion exchange resin particulates ortransfer membranes employed in electrochemical devices and methods mayalso be prepared by solubilizing a cross-linking monomer such asmethylene bisacrylamide (MBA), by pre-treatment with a caustic solution.The solubilized MBA may then be combined with an acrylic monomer, suchas dimethylaminopropylmethacrylamide, in a water soluble solvent andpolymerized. See U.S. Pat. Nos. 5,037,858 and 5,354,903 to MacDonald. Asin the previously identified technique, the resulting polymer may haveto be further reacted so that its pendant tertiary amine group isconverted to a quaternary ammonium salt to form the anion selectivepolymer. Alternatively, these patents teach combining the solubilizedMBA with an ionogenous acrylic monomer which has already undergonequaternization, such as methacrylamido-propyltrimethylammonium chloride,in a water soluble solvent and polymerizing the liquid mixture.

Accordingly, the above-identified technique requires a caustic solutionpretreatment step for solubilizing the cross-linking monomer. Further,as in the previously described technique, post-polymerizationquaternization may weaken the exchange resins and transfer membranesmade from such polymers. The alternative process involving use of anionogenous acrylic monomer requires a special solvent to prevent thequaternary ammonium salt from precipitating out of the liquid solutionbefore the polymerization occurs.

Thus, there is a need to develop caustic stable anion exchange resinsand transfer membranes with resilient surfaces and substantiallyleak-free transfer membranes for use in ion exchange and electrochemicalmethods and devices. Further, there is a need to develop simplifiedmethods of forming such exchange resins and transfer membranes whichavoid precipitation resulting from quaternization prior topolymerization. In addition, there is a need to develop simplifiedmethods of forming such exchange resins and transfer membranes whichavoid the necessity of washing steps associated with polymer formationprior to quaternization.

SUMMARY OF THE INVENTION

The present invention provides caustic-stable anion selective polymersfor forming exchange resins and transfer membranes as well as methods ofmaking the same. The present invention also provides devices and methodsemploying exchange resins and transfer membranes incorporating thesepolymers. The process of making the anion selective polymers of theinvention involves substantially simultaneous quaternization andpolymerization reactions. An ethylenic tertiary amine monomer is reactedwith an alkylating agent having a boiling temperature of at least about100° C., and a cross-linking agent in the presence of a polymerizationagent. Alternatively, an ethylenic tertiary amine monomer is reactedwith an alkylating agent having cross-linking capabilities and having aboiling temperature of at least about 100° C. in the presence of apolymerization agent.

In an aspect, the invention provides a polymer preparation processincluding combining an ethylenic tertiary amine monomer, an alkylatingagent having a boiling point of at least about 100° C. and across-linking agent in the presence of a polymerization agent at atemperature and for a time sufficient to form the polymer.

In an embodiment of this aspect of the invention, the monomers and theagent are combined in the presence of a solvent. In another embodimentof this aspect of the invention, the ethylenic tertiary amine isdimethylaminopropylmethacrylamide (DMAPMA), the alkylating agent isbutyl bromide, the cross-linking agent is divinylbenzene, and thesolvent is 2-pyrrolidone.

In another aspect, the invention provides a polymer preparation processincluding combining an ethylenic tertiary amine monomer and across-linking alkylating agent having a boiling temperature of at leastabout 100° C. in the presence of a polymerization agent at a temperatureand for a time sufficient to form the polymer. In an embodiment of thisaspect of the invention, the combining step is carried out in thepresence of a solvent. In another embodiment of this aspect of theinvention, the combining step is carried out in the presence of adiluent ethylenic monomer. If a solvent is present, then a diluentethylenic monomer soluble in the solvent is selected. Preferably, theethylenic tertiary amine monomer is DMAPMA, the cross-linking alkylatingagent is 1,6-dibromohexane, the diluent ethylenic monomer isN-vinylpyrrolidone, and the solvent is water.

In still another aspect of the invention, a compound having thefollowing formula is prepared.

In yet another aspect of the invention, a compound having the followingformula is prepared.

BRIEF DESCRIPTION OF THE DRAWING

The foregoing and other objects of the invention, the various featuresthereof, as well as the invention itself, may be more fully understoodfrom the following description, when read together with the accompanyingdrawing.

FIG. 1 is a schematic diagram of an electrodialysis device, whichincludes anion exchange transfer membranes prepared according to anaspect of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

One-step anion selective polymers are produced in accordance withprocesses of the present invention through substantially simultaneousquaternization/polymerization reactions. An ethylenic tertiary aminemonomer is reacted with an alkylating agent and a cross-linking agent inthe presence of a polymerization agent. Alternatively, an ethylenictertiary amine monomer is reacted with an alkylating agent havingcross-linking capabilities in the presence of a polymerization agent.The polymers of the present invention are substantially insoluble inaqueous solutions due to their cross-linkages.

The term “one-step” as used herein, as in for example, “one-step” anionselective polymers, refers to anion selective polymers produced bysubstantially simultaneous quaternization and polymerization reactions.

The term “quaternization/polymerization reaction”, as used herein,refers to substantially simultaneous quaternization and polymerizationreactions.

In one aspect of the present invention, one-step anion selectivepolymers are produced by reacting an ethylenic tertiary amine monomer,an alkylating agent having a boiling point of at least about 100° C. anda cross-linking agent. The reaction occurs in the presence of apolymerizing agent at a temperature and for a time sufficient to permitsubstantially simultaneous quatemization and polymerization of themonomers to form the polymer.

A typical structure of an ethylenic tertiary amine monomer useful inthis aspect of the invention is set forth below.

 Z=O, N—R₃

R₁=H, CH₃

R₂=CH₂_(n) n=0, . . . 20

R₃=H, CH₂_(m)CH₃ m=0, . . . 20

R₄, R₅=CH₂_(m)CH₃ m=0, . . . 20

Preferably, the ethylenic tertiary amine monomers used in this aspect ofthe invention are non-aromatic. More preferably, the ethylenic tertiaryamine monomer used in this aspect of the present invention is selectedfrom the group consisting of dimethylaminopropylmethacrylamide (DMAPMA),dimethylaminopropylacrylamide (DMAPAA), diethylaminopropylmethacrylamide(DEAPMA), dimethylaminoethylmethacrylate (DMAEMA) and mixtures thereof.Even more preferably, the ethylenic tertiary amine monomer is DMAPMA.Ethylenic tertiary amine monomers useful in this aspect of the presentinvention are commnercially available from, for example, Creanova,Somerset, N.J.

Alkylating agents suitable for use in this aspect of the presentinvention include alkyl halides having a boiling temperature of at leastabout 100° C. A typical structure of such an alkylating agent is setforth below.

 R—X

X=Cl, Br, I, C₇H₇SO₃—

OR

X—R—X

X=Cl, Br, I, C₇H₇SO₃

R=CH₂_(m) m=1 . . . 20

Preferably, the alkylating agent used in this aspect of the presentinvention is selected from the group consisting of butyl bromide (BuBr),hexyl chloride, benzyl chloride, butyl iodide, 1,6-dibromohexane,1,4-dibromobutane, 1,6-dichiorohexane, 1,4-dichlorobutane,1,10-diiododecane and mixtures thereof. More preferably, the alkylatingagent is BuBr and/or 1,6-dibromohexane. Alkylating agents useful in thisaspect of the present invention are commercially available from, forexample, Great Lakes Chemical Corp., West Lafayette, Ind.

Cross-linking agents suitable for use in this aspect of the inventionare capable of polymerizing with the ethylenic tertiary amine monomer ofthe reaction. Preferably, these cross-linking agents are substantiallystable to hydrolysis and caustic solutions. A typical structure of sucha cross-linking agent is set forth below.

 p=O, . . . 20

Z=O, N—R₃

R₁=H, CH₃, CH₂CH₃

R₂=CH₂_(n) n=1, . . . 20

R₃=H, CH ₂_(m)CH₃ m=0, . . . 20

Preferably, the cross-linking agents used in this aspect of the presentinvention include divinyl benzene (DVB), ethylene glycol dimethacrylate(EGDM), ethylene glycol diethacrylate, trimethylol propanetrimethacrylate (TMPTMA), trimethylol propane triethacrylate, methylenebisacrylamide, polyethylene glycol dimethacrylate, polyethylene glycoldimethacrylate, 1,6-dibromohexane, 1,4-dibromobutane,1,6-dichlorohexane, 1,4-dichlorobutane, 1,10-diiododecane and mixturesthereof. More preferably, the cross-linking agent is divinylbenzene.Cross-linking agents useful in this aspect of the present invention arecommercially available from, for example, Dow Chemical Co., Midland,Mich.; Riedel-DeHaen AG, Seelze, Germany, and Great Lakes ChemicalCorp., West Lafayette, Ind.

The cross-linking agent substantially ties or links together polymericchains into a network of polymers. The resulting polymeric network issubstantially insoluble and precipitates out from solvents insubstantially solid form. Without such cross-linking, the polymers ofthe invention would dissolve in water and thus, would be ineffective foruse as, for example, ion exchange membranes.

In an embodiment of this aspect of the invention, the monomer and theagents are combined in the presence of a solvent. Any solvent, ormixture thereof, is suitable for use in this embodiment of this aspectof the invention, so long as the solvent is not itself polymerizable.Solvents suitable in this embodiment of the invention include water,polyethylene glycols, dimethylsulfoxide, 2-pyrrolidone, N-methylpyrrolidone and mixtures thereof. More preferably, 2-pyrrolidone is thesolvent used in this embodiment of the invention. The non-aqueoussolvents useful in this aspect of the invention are commerciallyavailable from, for example, BASF, Parsippany, N.J.; Dow Chemical Co.,Midland, Mich.; and Gaylord Chemicals, Gainesville, Fla.

The quaternization/polymerization reaction of this aspect of the presentinvention is represented by the following non-limiting exemplaryreaction involving DMAPMA, BuBr and DVB as follows.

The quaternization/polymerization reaction of the present inventionoccurs in the presence of a polymerization agent. The polymerizationagent can include heat. The polymerization agent can also includevisible and ultraviolet radiation having a wavelength range of about 600nm to about 190 nm, electromagnetic radiation, electron beam radiation,polymerization initiating catalysts, chemical promoters and mixturesthereof.

The polymerization initiating catalysts include catalysts which arespontaneously active and catalysts which are activated by heat; byvisible, ultraviolet, electromagnetic or electron beam radiation asidentified above; or by chemical promoters. In general, the amount ofpolymerization initiating catalyst is about 0.1% to about 5.0% of theweight of the monomers employed in the polymerization reaction.

The term “chemical promoters”, as used herein, refers to a substancewhich increases the rate of polymerization either by itself or incombination with another polymerization agent. For example, methyl ethylketone peroxide can function as a polymerization agent by itself, butits rate of initiation can be greatly increased by small amounts oftransition metal salt chemical promoters such as, for example, cobaltnaphthenate. Similarly, dibenzoyl peroxide can function as apolymerization agent by itself, but its action can be accelerated by adimethyl aniline chemical promoter. The UV radiation polymerizationagents can become more efficient in the presence of chemical promoterswhich are photoinitiators, that is, chemical compounds which generatefree radicals. Non-limiting examples of such photoinitiating chemicalpromoters include benzophenone, benzil, anthraquinone, eosin andmethylene blue.

The quaternization/polymerization reaction can be performed at atemperature within the range of about 40° C. to about 150° C.Preferably, the reaction is performed at a temperature within the rangeof about 90° C. to about 100° C.

The anion selective polymers of this aspect of the present invention canbe synthesized using a wide range of relative proportions of ethylenictertiary amine monomers to alkylating agents to cross-linking agents.Preferably, the mixture contains about 10 mole % to about 70 mole % ofethylenic tertiary amine monomer to about 10 mole % to about 70 mole %of alkylating agent to about 90 mole % to about 30 mole % ofcross-linking agent.

In one aspect of the present invention, one-step anion selectivepolymers are produced by reacting an ethylenic tertiary amine monomer,an alkylating agent having a boiling point of at least about 100° C. anda cross-linking agent. The reaction occurs in the presence of apolymerizing agent at a temperature and for a time sufficient to permitsubstantially simultaneous quatemization and polymerization of themonomers to form the polymer.

The ethylenic tertiary amine monomers suitable for use in this aspect ofthe present invention include the ethylenic tertiary amine monomersidentified above. Preferably, the ethylenic tertiary amine monomers usedin this aspect of the invention are non-aromatic. More preferably, theethylenic tertiary amine monomers are dimethylaminopropylmethacrylamide(DMAPMA) and dimethylaminopropylacrylamide (DMAPAA). The ethylenictertiary amine monomers useful in this aspect of the invention areavailable from, for example, Creanova, Somerset, N.J.

The cross-linking alkylating agents suitable for use in this aspect ofthe present invention include alkyl multi-halides having a boiling pointtemperature of at least about 100° C. The general structure of such across-linking alkylating agent is set forth below.

X—R—X

X=Cl, Br, I, C₇H₇SO₃

R=—[—CH₂]_(m)— m=2, . . . 20

=—CH₂C₆H₅—

Preferably, cross-linking alkylating agents suitable in this aspect ofthe present invention include alkyl dihalides, such as 1,6-dibromohexane(DBH), 1,4-dibromobutane, 1,6-dichlorohexane, 1,4-dichlorobutane, and1,10-diiododecane. More preferably, the alkyl dihalide is DBH. Thecross-linking alkylating agents useful in this aspect of the inventionare commercially available from, for example, Riedel-DeHaen AG, Seelze,Germany, and Great Lakes Chemical Corp., West Lafayette, Ind.

In embodiments of the invention, the ethylenic tertiary amine and thecross-linking alkylating agent are combined in the presence of asolvent. The solvents suitable for this aspect of the invention includewater, polyethylene glycols, dimethylsulfoxide, 2-pyrrolidone, N-methylpyrrolidone and mixtures thereof. Preferably, the solvent is water. Somenon-aqueous solvents useful in this aspect of the invention arecommercially available from, for example, BASF, Parsippany, N.J.; DowChemical Co., Midland, Mich.; and Gaylord Chemicals, Gainesville, Fla.

In some embodiments of the invention, the ethylenic tertiary amines andcross-linking agents and the alkylating agents, or the ethylenictertiary amine monomers and the cross-linking alkylating agents arecombined with diluent ethylenic monomers. Any diluent ethylenic monomermay be employed so long as the diluent ethylenic monomer is capable ofpolymerizing with the ethylenic tertiary amine monomer of the one-stepquaternization/polymerization reaction and where a solvent is used, thediluent ethylenic monomer is soluble in the solvent employed.Preferably, the diluent ethylenic monomers are substantially stable tohydrolysis and caustic solutions. Further, non-aromatic diluentethylenic monomers are preferred since the resulting anion exchangestructures tend to be fouling resistant. The volume of the diluentethylennic monomer present during the reaction determines the percentporosity and substantially fixes the water holding capacity or contentof the resulting polymer. The diluent ethylenic monomer employed istypically about 10% to about 50% by volume of the final monomerformulation but can be more or less if so desired.

Where water is the selected solvent, the suitable diluent ethylenicmonomers include N-vinylpyrrolidinone (NVP), N-methylmethacrylamide,N,N-dimethylmethacrylamide, N-isopropylacrylamide, N-vinylformamide,N-methyl-N-vinylformamide and mixtures thereof. Preferably, the diluentethylenic monomer is NVP where water is the solvent.

The quaternization/polymerization reaction of the process involving thecombination of the ethylenic tertiary amine monomers and thecross-linking alkylating agents is represented by the followingnon-limiting exemplary reaction involving DMAPMA, DBH and NVP asfollows.

The reaction occurs in the presence of a polymerization agent, asdescribed above in the first aspect of the invention. The reaction canbe performed at a temperature within the range of about 40° C. to about150° C. Preferably, the reaction is performed at a temperature withinthe range of about 85° C. to about 110° C.

The anion selective polymers of this aspect of the present invention canbe synthesized using a wide range of ethylenic tertiary amine monomersto cross-linking alkylating agents to diluent ethylenic monomers.Preferably, the mixture contains about 50 mole % to about 100 mole % ofethylenic tertiary amine monomer to about 25 mole % to about 50 mole %of cross-linking alkylating agent to about 0 mole % to about 50 mole %of diluent ethylenic monomer.

The polymers formed using the processes set forth above can be used toform anion selective exchange resins and/or transfer membranes. Whenpolymers manufactured by the processes of the invention are used astransfer membranes, the transfer membrane can be formed by casting theliquid monomer mixture on a reinforcing

Anion selective exchange resins and transfer membranes formed frompolymers produced according to the processes of the present inventioncan be used in well-known ion exchange and electrochemical devices andmethods. FIG. 1 illustrates anion transfer membranes 22 formed withanion selective polymers 23 formed according to the processes of theinvention.

The following examples illustrate the preferred modes of making andpracticing the present invention, but are not meant to limit the scopeof the invention since alternative methods can be used to obtain similarresults.

EXAMPLE ONE

Thirty-one (31) volume % dimethylaminopropylmethacrylamide (DMAPMA)ethylenic tertiary amine was mixed with 19 volume % of butyl bromide(BuBr) alkylating agent and 18 volume % of divinylbenzene (DVB)cross-linking agent in 32 volume % of 2-pyrrolidone solvent at roomtemperature of approximately 70° F. in the presence of 0.1 volume % oftertiary butyl peroctanoate (TPO) catalyst.

After complete dissolution of the mixture, the liquid mixture was addedto a acrylic cloth reinforcing substrate to form sample membrane. Thecast membrane was cured between glass plates at 100° C. temperature forapproximately thirty (30) minutes.

The sample membrane was characterized following standard ion exchangemembrane characterization procedures, as shown in Table I below.

TABLE I Membrane A Characteristics Water Water Transport Capacitycontent Resistivity Thickness Transport No. (meq/g) (%) (ohm-cm²) (cm)No. (mL/F) 2.72 41.1 9.8 .056 .971 92

The anion exchange capacity was expressed as milligram-equivalents pergram of dry anion exchange resin in the nitrate form (i.e., notincluding fabric). The water content was expressed as percent by weightof the wet anion exchange resin in the nitrate form (i.e., not includingfabric). The areal resistance of a square centimeter of membrane in thechloride form was measured in 0.01N NaCl at 1000 Hz. The transport no.indicated the efficiency of the membrane in transporting anions asdetermined potentiometrically between solutions of 1.0N NaCl and 0.5NNaCl. The water transport no., which indicated the volume of waterflowing, upon passage of an electric current between solutions of 0.6NNaCl was expressed in milliliter/Faraday.

Caustic stability of the membranes made using the process above was alsotested by soaking the membranes in 1N NaOH at room temperature of about70° F. Performance of the membrane over time is summarized in Table IIbelow.

TABLE II Performance Of Membrane A Over Time Caustic Solution Water SoakTime Capacity content (days) (meq/g) (%)  0 2.72 41.1  1 2.78 40.4  62.66 41.6 13 2.63 42.8 15 2.69 44.1 20 2.6  44.5 27 2.49 44.3 37 2.4946  

EXAMPLE TWO

In this example, 27 weight % of the ethylenic tertiary amine monomerdimethylaminopropyl methacrylamide (DMAPMA) was mixed with 13 weight %of the diluent ethylenic monomer N-vinylpyrrolidone (NVP) in 40 weight %of water as a solvent. Approximately 19 weight % of 1,6-dibromohexane(DBH) was added as a cross-linking alkylating agent. The mixture wasinitially heated to 70° C. and then cooled to about 25° C. The watersoluble catalyst VA04™ (produced by Wako Chemicals USA, Inc., Richmond,Va.) in the amount of 1 weight percent was added to the mixture. Aftercomplete dissolution of the mixture, the mixture was cast onto acryliccloth reinforcing substrate to form sample membrane B. The cast membranewas cured between glass plates at approximately 85° C. for approximatelythirty (30) minutes.

The sample membrane B was characterized following standard ion exchangecharacterization procedures, as described above in Example One. Theproperties of the membrane are set forth below in Table III.

TABLE III Membrane B Characteristics Water Water Transport Capacitycontent Resistivity Thickness Transport No. (meq/g) (%) (ohm-cm²) (cm)No. (mL/F) 2.80 42.6 9.3 .051 .968 90

Although a few exemplary embodiments of this invention have beendescribed in detail above, those skilled in the art will readilyappreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. For example, a variety of solvents may beused. Accordingly, all such modifications are intended to be includedwithin the scope of this invention as defined in the following claims.

We claim:
 1. A compound having the formula


2. The polymer of claim 1 produced by the process comprising the step ofcombining into a mixture at least one ethylenic tertiary amine monomerwith at least one crosslinking alkylating agent having a boilingtemperature of at least 100° C. in the presence of a diluent ethylenicmonomer and a polymerization agent for a time and at a temperaturesufficient to form the polymiier, where in the ethylenic tertiary aminemonomer is dimethylaminopropylmethacrylamide, the crosslinkingalkylating agent is 1,6-dibomohexane, and the diluent ethylenic monomeris N-vinyl pyrrolidinone.
 3. The polymer produced by the process ofclaim 2, wherein the combining step is carried out in the presence of asolvent.
 4. The polymer produced by the process of claim 2, wherein thesolvent is water.
 5. The polymer produced by the process of claim 4,wherein the ethylenic tertiary amine, the cross-linking alkylatingagent, the diluent monomer, and the solvent are combined in the presenceof a reinforcing substrate.
 6. The polymer produced by the process ofclaim 5, wherein the reinforcing substrate is selected from the groupconsisting of synthetic fabric, glass fiber cloth, polyvinylidenechloride screen, glass paper, treated cellulose battery paper,polystyrene-coated glass fiber mat, and polyvinyl chloride batterypaper.
 7. The polymer produced by the process of claim 5 wherein thereinforcing substrate is polypropylene cloth.
 8. The polymer produced bythe process of claim 2 wherein the mixture contains about 50 molepercent to about 100 mole percent of ethylenic tertiary amine monomer toabout 25 mole percent to about 50 mole percent of crosslinkingalkylating agent to about 50 mole percent to greater that 0 mole percentof diluent ethylenic monomer.